With Johnny Manziel's Heisman Trophy win in 2012, the importance of freshmen in the college game has been further established. First-year players have been making an impact in the college game long before Manziel took home the game's highest award, and these five incoming freshman have the best shots to be next year's instant impact players.

Michigan has not had a running back be the focal point of their offense since Mike Hart left Ann Arbor following the 2007 season.

In Green, the Wolverines expect they have found that back to build their offense around. Plenty of high school stars have entered college with the ability to impact immediately, but failed to do so because of factors other than their talent. The 6-foot, 220-pound Green has shown the work ethic and drive to reach his potential -- dropping 50 pounds since starting his high school career and becoming one of the most physically impressive runners in the country. The Wolverines' returning starter at running back, Fitzgerald Touissant, suffered a broken leg in the 11th game of the regular season that required surgery. He is not expected to be a full participant in spring practices, and his status for the start of the 2013 season remains uncertain. Green, meanwhile, embodies the style of back the Wolverines are looking to feature in their continuing transition to a pro-style offense.

The 6-foot-6, 230-pound Howard is the highest-ranked tight end since Martellus Bennett in the class of 2005. Bennett is now entering his sixth season in the NFL, and it looks pretty likely Howard will one day be playing on Sundays as well. In the meantime, the nation's No. 16 prospect heads to an Alabama team that will be looking to replace its leading receiver at tight end -- senior Michael Williams -- on a roster that only has a combined eight career receptions coming back. Talent and opportunity is the recipe for an instant impact freshman. Howard has the talent and the Crimson Tide will provide the opportunity. The one question with Howard is the level of talent he played against in high school, but the five-star had no trouble adjusting to Division I talent when he went against the nation's best at the Rivals100 Five-Star Challenge this summer.

The nation's No. 1 prospect still needs some refinement at his position and will not reach his full potential until later in his playing career, but Nkemdiche's skill set is such that he can dominate immediately on pure athletic ability alone. That's not to say Nkemdiche is raw, he just has a ceiling he has not yet reached. The 6-foot-5, 260-pounder has college-level strength right now, an explosive first step, plays with great leverage and relentlessly pursues the quarterback. Expect him to face double teams immediately as a freshman because even against the nation's top offensive tackles at the Under Armour All-American Game last month, none could handle the five-star defensive end one-on-one. Nkemdiche is an every-down defensive end who should develop into a feared pass rusher, while also being a stout run defender.

Ole Miss started rising on Treadwell's list of favorites after the five-star receiver had a chance to attend one of the Rebels' home games early in the season and saw that head coach Hugh Freeze was not afraid to throw the ball deep to standout wide receiver sophomore wide receiver Donte Moncrief. SEC teams will not be sleeping on Moncrief next fall after he caught 10 touchdowns in 2012, which should mean plenty of looks Treadwell's direction from quarterback Bo Wallace. Assuming that Treadwell, as a freshman, is going to be the beneficiary of added attention Moncrief's direction is not premature. The 6-foot-3, 198-pound receiver could have helped several BCS schools last season. He is one of the most complete receivers to come out of the high school ranks in some time, and we hear Ole Miss coaches are serious about using Treadwell early and often in his collegiate career.

Under head coach Chip Kelly Oregon's offense was known for their quick-strike scoring ability. That offensive style is expected to remain intact now that Kelly's offensive coordinator, Mark Helfrich, has replaced his former boss after Kelly made the move to the NFL. The 6-foot, 200-pound Tyner certainly has quick-strike scoring ability, demonstrated by his 47 touchdowns as a high school senior, which included an amazing 10 touchdowns in a single game. Oregon's leading rusher from the 2012 season, Kenjon Barner, is on his way to the NFL Draft in April. The Ducks always seem to have a stable of running backs ready to step in and step up, but who else on the roster has Tyner's combination of speed, agility and the frame to carry the ball 20-plus times a game? His performance at the U.S. Army All-American Bowl proved the five-star back's skill set holds up against Division I competition.